The correct answer is: a) Cloudbursts.
Cloudbursts are a sudden and heavy downpour of rain that can cause flash floods. They are often caused by thunderstorms that form over mountains or other high ground. The rain from a cloudburst can fall at a rate of several inches per hour, which can quickly overwhelm rivers and streams. This can cause flash floods, which can move with great speed and force. Flash floods can damage property, destroy crops, and even cause loss of life.
Cyclones are large, rotating storms that form over warm ocean waters. They can cause heavy rain, high winds, and storm surges. However, cyclones are not typically associated with flash floods.
Dam failures can also cause flash floods. However, dam failures are relatively rare events.
Snowmelt can also cause flash floods, but this is more common in mountainous areas. When snow melts quickly, it can cause a sudden increase in the flow of water in rivers and streams. This can lead to flash floods.
In conclusion, the correct answer is: a) Cloudbursts.